How to train myself for american football?

I played american football in high school and was pretty good. I was more focused on grades than football so I didnt pursue it in college. What you need to do is find exactly what position you are. If very few people play american football then you dont really know what is good and what is bad. If you can are 13 and want to be a good quarterback then you should be able to throw the ball 30 to 40 meters, or 35 yards. If you are not very tall than maybe you should try to be a running back. American Football is all about playing to your strengths. If you are not very fast than you need to be strong and if you are not very strong then you need to be really fast. Your ultimate goal should be a good mixture of strength and speed. You also need to have the will power to keep going even when your body is hurting. You really need to start lifting weights as soon as you start puberty. Many people will say that you should weight until 16 or 17 years but I think that is too old to start. If you know you are going to be short, then you should starting weight lifting even earlier.